My son has an '03 DRZ125 and wev'e been battleing this problem as well. It's hard to find aftermarket parts for these bikes. I tried some ERC brake shoes which were a bit better for a while. I just got some stintered shoes by a european? company ,of which the name escapes me. I will report back if they are a significant improvement, but I'm not holding my breath. The rear ,and to some extent front, brakes on this otherwise decent bike are atrocious. Paticularly if you ride through a lot of water. It's a frustating problem. This is my kids first bike and he ends up dragging his feet to stop in wet conditions!